Is300H Poor Battery Life And Now...

alpine · May 8, 2015

I was away for about 3 weeks over Christmas and when I returned, I found the IS300H would not start. I had to call Lexus assistance who got the car going with the aid of one of those Battery packs. They told me to run it for at least 30mins before stopping the engine. I stupidly ignored that advice and only ran it for about 15mins.
Sure enough, it wouldn't start when I stopped it for about an hour, and I had to call roadside assistance again.

I've just been away for 2 weeks until today, and yet again the car will not go. Even worse, this time there is insufficient power in the Battery to allow the locks to operate.

After my initial experience, I bought one of those RAC Battery packs so I would have a solution if the problem recurred.
Simple, just open the bonnet attach the pack and I would be away. Except the remote would not operate the door locks. No problem, detach the little mechanical key from the fob and open the car with that. But, neither of the keys within the 2 fobs will operate the mechanical lock.
Clearly there is no point in calling Lexus Assistance since that service is simply rebadged AA recovery and they won't have some master key.
So I'm stuck at home and will be calling my Lexus dealer tomorrow to try to get something sorted.

This is my third new Lexus, but I'm now beginning to go off the marque....

ColinBarber · May 8, 2015

I'd suggest the keys will operate the locks, however you need to use a lot of force because you have no leverage with such a small handle on the key. The same thing happened with my Father's Prius, he didn't have the strength needed to pull the mechanical locks.

Once you get into the vehicle I'd recommend the Battery terminals are checked to make sure they are tight. There have been a couple of members who have experienced this and extra resistance from a loose terminal would make the standby Battery life worse.

There is the possibility that completely draining the Battery the first time has damaged it and so it's capacity is reduced. I'd investigate getting a new Battery under warranty if you cannot leave your vehicle for only 2 weeks.

alpine · May 8, 2015

Thank you Colin, you're right. With a mole wrench on the end of the key, and seemingly in danger of breaking the key off in the lock, it's opened the lock so now I can attach the jumper Battery...

Edit: In fact the torque needed to turn the key until it clicked was such that the key did bend a little and needed a little unbending to get it to fit back in the fob!

is200 Newbie · May 8, 2015

Is it worth a squirt of WD40 into the locks for those of us who have not used them since owning their cars or is it just a quirk of the car locks?

C Mclean · May 8, 2015

Happened to me. The car was left for about 3 hours, I came back and nothing??, used the metal key to get into the boot and found the Battery terminals were loose. Gave them a thump and then got Lexus to tighten my nuts...

ColinBarber · May 9, 2015

Is it worth a squirt of WD40 into the locks for those of us who have not used them since owning their cars or is it just a quirk of the car locks?

Worth doing once a year (dealers used to do this as part of the service years ago, doubt they bother now) but most of the resistance is from the locking mechanism rather than the key barrel.

alpine · May 9, 2015

When the weather gets a little more bearable, or I've got used to the vile British climate again, I will check the connections in the boot..

the key could do with a redesign really, so it has a fold out handle or something similar. Meanwhile, I will carry a mole wrench... Or does it have a tool kit with a pair of pliers like the GS had? I've never looked.

capese21 · May 9, 2015

If the Battery was dead then running the engine for 30 minutes will have no effect on its state of charge. It is a misconception to assume that driving a car with a flat Battery will charge it up fully.

Your Battery is either defective or needs a Battery charger on it for a few hours. The alternator is only there to top up a fully charged Battery not bring it back from the dead.

Maybe the Lexus system hybrid is different but I doubt it.

Ed

Roscobbc · May 9, 2015

If the battery was dead then running the engine for 30 minutes will have no effect on its state of charge. It is a misconception to assume that driving a car with a flat battery will charge it up fully.

Your battery is either defective or needs a battery charger on it for a few hours. The alternator is only there to top up a fully charged battery not bring it back from the dead.

Maybe the Lexus system hybrid is different but I doubt it.

Ed

One would presume that because the 'starter' Battery doesn't actually operate a conventional starter motor as such (which can be quite a power consuming accessory) the power requirements are less (size of Battery certainly bears that out)

stevet · May 10, 2015

Does the it even have an alternator? Or just charged from the traction batteries

capese21 · May 10, 2015

Ok I have had a read and no there is not an alternator as such driven from a rubber belt. It then points towards a faulty Battery. Although however the Battery is charged it would need more than 30 mins to bring it back from flat imho.

Lexus did a Hybrid health check on my IS at the last service which gave a readout of all the systems.

Ed

ColinBarber · May 10, 2015

Correct there is no alternator, the hybrid system provides the 12v feed once in 'Ready' mode and will charge the aux Battery. It would certainly need more than 30 minutes to achieve a full charge, however over the course of 4 months I would expect it to have fully charged it, depending on your usage habits.

alpine · May 11, 2015

Since the weather has improved a little, I had a look in the boot a few minutes ago and found the Battery tucked away in the left rear wing panel. Connections seem to be adequately tight, but of course one could get a bit more on the terminal clamps. But then one always can with pressed steel clamps. More intriguing were the two items sealed in yellow polythene in the tray above the Battery. One appears to be get you home tyre foam. Curiously, this had water droplets on top of the polythene cover. Whether this means the car has a leak somewhere in that area I'm not sure. I couldn't see any associated corrosion in the vicinity of the Battery.

MONTIMAR · January 20, 2018

Last October I picked a dry day, ran the car into the garage, connected a maintenance Battery charger to the 12 volt connection under the bonnet, left the car unlocked with the hand brake off, nailed the garage door shut and went Back Packing to South East Asia for 14 weeks. On my return yesterday I restarted the car and ran it for 30 miles. No drama no problems. I was as if I had never been away, I was quite impressed.

alpine · January 20, 2018

Yes, I bought one of the Ctek chargers last year, and this works OK.

MONTIMAR · January 20, 2018

Yes, my maintenance charger is also a Ctek. I think they are one of the best on the market.

rayaans · January 20, 2018

On 11/05/2015 at 4:36 PM, alpine said:

Since the weather has improved a little, I had a look in the boot a few minutes ago and found the battery tucked away in the left rear wing panel. Connections seem to be adequately tight, but of course one could get a bit more on the terminal clamps. But then one always can with pressed steel clamps. More intriguing were the two items sealed in yellow polythene in the tray above the battery. One appears to be get you home tyre foam. Curiously, this had water droplets on top of the polythene cover. Whether this means the car has a leak somewhere in that area I'm not sure. I couldn't see any associated corrosion in the vicinity of the battery.

TBH I think you have a dud Battery.

Mine is left for over 3 weeks sometimes and starts first time - its a 63 plate as well so one of the early models. I believe it had its Battery changed before it even got to the 1st owner though as the first one was not right.

Martin F · January 20, 2018

@rayaans You do realise that post is over two years old now?

Hopefully he has sorted his issue

rayaans · January 21, 2018

6 hours ago, Martin F said:

@rayaans You do realise that post is over two years old now?

Hopefully he has sorted his issue

Lol didn't realise until I looked at the date. Seems like OP revived his own thread though!

BrunoLeal · June 24, 2019

Writing here so I don't create a new post about the same topic.

Any idea on how to manage this when you have no electricity plug available to connect a maintenance Battery to the car?

I have a portable remote charger boost which I used today after the car was parked for 15 days and had not enough Battery charge to start properly.

Soon I'll be 3 weeks away and wanted to avoid the Battery to be completely empty when back.

thanks,

Bruno

Herbie · June 24, 2019

Sounds like you need one of these https://www.amazon.co.uk/AA-5060114614185-Solar-Powered-Battery-Charger/dp/B00AC1LLQY

Britprius · June 24, 2019

31 minutes ago, BrunoLeal said:

Writing here so I don't create a new post about the same topic.

Any idea on how to manage this when you have no electricity plug available to connect a maintenance battery to the car?

I have a portable remote charger boost which I used today after the car was parked for 15 days and had not enough battery charge to start properly.

Soon I'll be 3 weeks away and wanted to avoid the battery to be completely empty when back.

thanks,

Bruno

Disconnecting one of the Battery terminals "preferably the negative for safety reasons" is perhaps the simplest way, but this will mean re programing the electric windows, and such after re connection. The other aternative is to use a solar charger.

John

BrunoLeal · June 24, 2019

Unfortunately I live in a estate with underground parking but no access to electricity plugs.

Is there any option for portable Battery maintenance? Something like the boost device I have but to keep Battery loaded for a few weeks?

Many thanks guys,

Bruno

Herbie · June 24, 2019

45 minutes ago, BrunoLeal said:

Unfortunately I live in a estate with underground parking but no access to electricity plugs.

Is there any option for portable battery maintenance?

Yes, the solar panel I linked to above. It works with either natural daylight or artificial lights from underground car parks - probably not as well, but it does work.

I'm assuming you have a jump start Battery pack, which is the thing you refer to as "a portable remote charger boost" that looks something like the picture below? If so, then no, there's nothing like that that you could keep connected because the Battery in that would just go flat like your proper car Battery does.

You've only got four options:

Access to mains so that you can use a trickle charger
Solar panel
Battery goes flat and you use a jump start Battery pack when you get back.
Disconnect negative terminal from 12V Battery and put up with having to reset windows, power locks etc.

reeac · June 25, 2019

This topic came up last year and I related my experiences and problems then. Subsequently I bought a small digital voltmeter which fits easily into the central storage compartment being plugged into the cigarette lighter socket there where it sees the full 12 volt battery voltage. I now always check that voltage as I press the start button. I've been surprised to see that the Battery voltage is always under 12 volts and I've seen as low as 11.6 volts if the car hasn't been driven for 5-6 days. This seems to me to be quite different from normal 12 V batteries which generally show 12.5 - 12.6 volts. The charging system seems to be fine ..... the Battery voltage immediately rises to 14.0 to 14.3 volts as it receives charge from the traction Battery. What I don't know is what the minimum voltage is to operate the locks and to start up the electronics. A tip for anyone buying a voltmeter for this purpose: buy one with the plug and meter connected by a short lead .... not an all in one unit. With the latter you won't be able to read the display when it's plugged in.